1 /*
2 * Altera University Program PS2 controller driver
3 *
4 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
5 *
6 * Based on sa1111ps2.c, which is:
7 * Copyright (C) 2002 Russell King
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/input.h>
17 #include <linux/serio.h>
18 #include <linux/interrupt.h>
19 #include <linux/platform_device.h>
20 #include <linux/io.h>
21 #include <linux/slab.h>
22 #include <linux/of.h>
23
24 #define DRV_NAME "altera_ps2"
25
26 struct ps2if {
27 struct serio *io;
28 struct resource *iomem_res;
29 void __iomem *base;
30 unsigned irq;
31 };
32
33 /*
34 * Read all bytes waiting in the PS2 port. There should be
35 * at the most one, but we loop for safety.
36 */
altera_ps2_rxint(int irq,void * dev_id)37 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
38 {
39 struct ps2if *ps2if = dev_id;
40 unsigned int status;
41 int handled = IRQ_NONE;
42
43 while ((status = readl(ps2if->base)) & 0xffff0000) {
44 serio_interrupt(ps2if->io, status & 0xff, 0);
45 handled = IRQ_HANDLED;
46 }
47
48 return handled;
49 }
50
51 /*
52 * Write a byte to the PS2 port.
53 */
altera_ps2_write(struct serio * io,unsigned char val)54 static int altera_ps2_write(struct serio *io, unsigned char val)
55 {
56 struct ps2if *ps2if = io->port_data;
57
58 writel(val, ps2if->base);
59 return 0;
60 }
61
altera_ps2_open(struct serio * io)62 static int altera_ps2_open(struct serio *io)
63 {
64 struct ps2if *ps2if = io->port_data;
65
66 /* clear fifo */
67 while (readl(ps2if->base) & 0xffff0000)
68 /* empty */;
69
70 writel(1, ps2if->base + 4); /* enable rx irq */
71 return 0;
72 }
73
altera_ps2_close(struct serio * io)74 static void altera_ps2_close(struct serio *io)
75 {
76 struct ps2if *ps2if = io->port_data;
77
78 writel(0, ps2if->base); /* disable rx irq */
79 }
80
81 /*
82 * Add one device to this driver.
83 */
altera_ps2_probe(struct platform_device * pdev)84 static int __devinit altera_ps2_probe(struct platform_device *pdev)
85 {
86 struct ps2if *ps2if;
87 struct serio *serio;
88 int error, irq;
89
90 ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
91 serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
92 if (!ps2if || !serio) {
93 error = -ENOMEM;
94 goto err_free_mem;
95 }
96
97 serio->id.type = SERIO_8042;
98 serio->write = altera_ps2_write;
99 serio->open = altera_ps2_open;
100 serio->close = altera_ps2_close;
101 strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
102 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
103 serio->port_data = ps2if;
104 serio->dev.parent = &pdev->dev;
105 ps2if->io = serio;
106
107 ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
108 if (ps2if->iomem_res == NULL) {
109 error = -ENOENT;
110 goto err_free_mem;
111 }
112
113
114 irq = platform_get_irq(pdev, 0);
115 if (irq < 0) {
116 error = -ENXIO;
117 goto err_free_mem;
118 }
119 ps2if->irq = irq;
120
121 if (!request_mem_region(ps2if->iomem_res->start,
122 resource_size(ps2if->iomem_res), pdev->name)) {
123 error = -EBUSY;
124 goto err_free_mem;
125 }
126
127 ps2if->base = ioremap(ps2if->iomem_res->start,
128 resource_size(ps2if->iomem_res));
129 if (!ps2if->base) {
130 error = -ENOMEM;
131 goto err_free_res;
132 }
133
134 error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if);
135 if (error) {
136 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n",
137 ps2if->irq, error);
138 goto err_unmap;
139 }
140
141 dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq);
142
143 serio_register_port(ps2if->io);
144 platform_set_drvdata(pdev, ps2if);
145
146 return 0;
147
148 err_unmap:
149 iounmap(ps2if->base);
150 err_free_res:
151 release_mem_region(ps2if->iomem_res->start,
152 resource_size(ps2if->iomem_res));
153 err_free_mem:
154 kfree(ps2if);
155 kfree(serio);
156 return error;
157 }
158
159 /*
160 * Remove one device from this driver.
161 */
altera_ps2_remove(struct platform_device * pdev)162 static int __devexit altera_ps2_remove(struct platform_device *pdev)
163 {
164 struct ps2if *ps2if = platform_get_drvdata(pdev);
165
166 platform_set_drvdata(pdev, NULL);
167 serio_unregister_port(ps2if->io);
168 free_irq(ps2if->irq, ps2if);
169 iounmap(ps2if->base);
170 release_mem_region(ps2if->iomem_res->start,
171 resource_size(ps2if->iomem_res));
172 kfree(ps2if);
173
174 return 0;
175 }
176
177 #ifdef CONFIG_OF
178 static const struct of_device_id altera_ps2_match[] = {
179 { .compatible = "ALTR,ps2-1.0", },
180 {},
181 };
182 MODULE_DEVICE_TABLE(of, altera_ps2_match);
183 #else /* CONFIG_OF */
184 #define altera_ps2_match NULL
185 #endif /* CONFIG_OF */
186
187 /*
188 * Our device driver structure
189 */
190 static struct platform_driver altera_ps2_driver = {
191 .probe = altera_ps2_probe,
192 .remove = __devexit_p(altera_ps2_remove),
193 .driver = {
194 .name = DRV_NAME,
195 .owner = THIS_MODULE,
196 .of_match_table = altera_ps2_match,
197 },
198 };
199
altera_ps2_init(void)200 static int __init altera_ps2_init(void)
201 {
202 return platform_driver_register(&altera_ps2_driver);
203 }
204 module_init(altera_ps2_init);
205
altera_ps2_exit(void)206 static void __exit altera_ps2_exit(void)
207 {
208 platform_driver_unregister(&altera_ps2_driver);
209 }
210 module_exit(altera_ps2_exit);
211
212 MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
213 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
214 MODULE_LICENSE("GPL");
215 MODULE_ALIAS("platform:" DRV_NAME);
216